Thanks to the forum for advice to solve my steering wheel shake or "shimmy".
 It varied from none to lots, braking or not braking, but the worst was while braking.
 Turns out it was 2 things, firstly the after-market wheels were not a snug fit to the the hub spigot.
Depending on how off-centre each time the wheels were remounted, determined the amount of shake while not braking.
Thanks to @redtarga for that tip - solved by hub centric rings.$10
 This left some shake, but only when braking. Easy diagnosis - solved by machining the front rotors $50.
 At last, a "quiet" steering wheel.   
    Hope this will help others - I had never heard of "hub centric", presuming the studs took care of that. Wrong.